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Lecture 1: RDCH 702 Introduction

Lecture 1: RDCH 702 Introduction. Class organization Outcomes Grading Chart of the nuclides Description and use of chart Data Radiochemistry introduction Atomic properties Nuclear nomenclature X-rays Types of decays Forces. RDCH 702: Introduction. Outcomes for RDCH 702

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Lecture 1: RDCH 702 Introduction

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  1. Lecture 1: RDCH 702 Introduction • Class organization • Outcomes • Grading • Chart of the nuclides • Description and use of chart • Data • Radiochemistry introduction • Atomic properties • Nuclear nomenclature • X-rays • Types of decays • Forces

  2. RDCH 702: Introduction • Outcomes for RDCH 702 • Understand chemical properties in radiation and radiochemistry • Use and application of chemical kinetics and thermodynamics to evaluate radionuclide speciation • Understand the influence of radiolysis on the chemistry of radioisotopes • Understand and evaluate radioisotope production • Evaluate and compare radiochemical separations • Utilization of radioisotope nuclear properties in evaluating chemical behavior • Use and explain the application of radionuclides in research • Discuss and understand ongoing radiochemistry research

  3. Grading • Homework (5 %) • In class quiz at completion of topic • Quizzes (12.5 % each) • Take home quiz • Develop tools for research (spreadsheets) • Presentation (20 %) • Based on recent literature • End of semester • 20-25 minutes • Classroom participation (12.5 %) • Bring chart of the nuclides! • Class developed to assist and compliment research activities

  4. Schedule

  5. Types of Decay 1.  decay (occurs among the heavier elements) 2.  decay 3. Positron emission 4. Electron capture 5. Spontaneous fission

  6. Fission Products • Fission yield curve varies with fissile isotope • 2 peak areas for U and Pu thermal neutron induced fission • Variation in light fragment peak • Influence of neutron energy observed 235U fission yield

  7. Photon emission • Gamma decay • Emission of photon from excited nucleus • Metastable nuclide (i.e., 99mTc) • Following decay to excited daughter state • X-ray • Electron from a lower level is removed • electrons from higher levels occupy resulting vacancy with photon emission • De-acceleration of high energy electrons • Electron transitions from inner orbitals • X-ray production • Bombardment of metal with high energy electrons • Secondary x-ray fluorescence by primary x-rays • Radioactive sources • Synchrotron sources

  8. X-rays • Removal of K shell electrons • Electrons coming from the higher levels will emit photons while falling to this K shell • series of rays (frequency n or wavelength l) are noted as Ka, Kb, Kg • If the removed electrons are from the L shell, noted as La, Lb, Lg • In 1913 Moseley studied these frequencies n, showing that: • where Z is the atomic number and, A and Z0 are constants depending on the observed transition. • K series, Z0 = 1, L series, Z0 = 7.4.

  9. Chart of the Nuclides • Presentation of data on nuclides • Information on chemical element • Nuclide information • Spin and parity (0+ for even-even nuclides) • Fission yield • Stable isotope • Isotopic abundance • Reaction cross sections • Mass • Radioactive isotope • Half-life • Modes of decay and energies • Beta disintegration energies • Isomeric states • Natural decay series • Reaction cross sections • Fission yields for isobars

  10. Chart of Nuclides • Decay modes • Alpha • Beta • Positron • Photon • Electron capture • Isomeric transition • Internal conversion • Spontaneous fission • Cluster decay

  11. Chart of the Nuclides Questions • How many stable isotopes of Ni? • What is the mass and isotopic abundance of 84Sr? • Spin and parity of 201Hg? • Decay modes and decay energies of 212Bi • What are the isotopes in the 235U decay series? • What is the half-life of 176Lu? • What is the half-life of 176Yb • How is 238Pu produced? • How is 239Pu made from 238U • Which actinide isotopes are likely to undergo neutron induced fission? • Which isotopes are likely to undergo alpha decay?

  12. Table of the Isotopes • Detailed information about each isotope • Mass chain decay scheme • mass excess (M-A) • Mass difference, units in energy (MeV) • particle separation energy • Populating reactions and decay modes • Gamma data • Transitions, % intensities • Decay levels • Energy, spin, parity, half-life • Structure drawing

  13. Radiochemistry Introduction • Radiochemistry • Chemistry of the radioactive isotopes and elements • Utilization of nuclear properties in evaluating and understanding chemistry • Intersection of chart of the nuclides and periodic table • Atom • Z and N in nucleus (10-14 m) • Electron interaction with nucleus basis of chemical properties (10-10 m) • Electrons can be excited • Higher energy orbitals • Ionization • Binding energy of electron effects ionization • Isotopes • Same Z different N • Isobar • Same A (sum of Z and N) • Isotone • Same N, different Z • Isomer • Nuclide in excited state • 99mTc

  14. Terms and decay modes: Utilization of chart of the nuclides • Identify the isomer, isobars, isotones, and isotopes • 60mCo, 57Co, 97Nb, 58Co, 57Ni, 57Fe, 59Ni, 99mTc • Identify the daughter from the decay of the following isotopes • 210Po (alpha decay, 206Pb) • 196Pb • 204Bi (EC decay, 204Pb) • 209Pb • 222At • 212Bi (both alpha and beta decay) • 208Pb (stable) • How is 14C naturally produced • Reactions with atmosphere (14N as target) • Identify 5 naturally occurring radionuclides with Z<84

  15. Half Lives • N/No=e-t • N=Noe- t • =(ln 2)/t1/2 • l is decay constant • No=number at time zero (atoms, mass, moles) • N= number at time t Rate of decay of 131I as a function of time.

  16. Equation questions • Calculate decay constant for the following • 75Se example • l= ln(2)/119.78 day = 0.00579 d-1 • l= 0.00579 d-1 *1d/24 hr * 1 hr/3600 s =6.7E-8 s-1

  17. Equation Questions • What percentage of 66As remains from a given amount after 0.5 seconds • Use N/No=e-t • t1/2 = 95.6 ms; l=7.25 s-1 • N/No=e-t = N=/No=e-7.25(.5) = 0.0266 =2.66 % • After 5.23 half lives • How long would it take to decay 90 % of 65Zn? • Use N/No=e-t • 90 % decay means 10 % remains • Set N/No=0.1, t1/2 = 244 d, l= 2.84E-3 d-1 • 0.1=e-2.84E-3t • ln(0.1)= -2.84E-3 d-1 t • =-2.30/-2.84E-3 d-1 = t =810 days

  18. Equation Questions • If you have 1 g of 72Se initially, how much remains in 12 days? • t1/2 = 8.5 d, l=8.15E-2 d-1 • N=Noe- t • N=(1 g) e- 8.15E-2(12) • N=0.376 g • What if you started with 10000 atoms of 72Se, how many atoms after 12 days? • 0.376 (37.6 %) remains • 10000(0.376) = 3760 atoms

  19. What holds the nucleus together: Forces in nature • Four fundamental forces in nature • Gravity • Weakest force • interacting massive objects • Weak interaction • Beta decay • Electromagnetic force • Most observable interactions • Strong interaction • Nuclear properties

  20. Particle Physics: Boundary of Course • fundamental particles of nature and interaction symmetries • Particles classified as fermions or bosons • Fermions obey the Pauli principle • antisymmetric wave functions • half-integer spins • Neutrons, protons and electrons • Bosons do not obey Pauli principle • symmetric wave functions and integer spins • Photons

  21. Standard Model • Boson are force carriers • Photon, W and Z bosons, gluon • Integer spin

  22. Topic review • Types of radioactive decay • Understand and utilize the data presented in the chart of the nuclides • Units for data • Relationships between isotopes • Fission yields • Identify common fission products • Define X-rays • Read introduction to chart of the nuclides

  23. Study Questions • What are the course outcomes? • What are 3 isotones of 137Cs • What are the different types of radioactive decay? • Provide 5 radioelements • Why is Tc naturally radioactive • What are the stable isotopes of Sn? • What is the beta decay energy of 90Sr? • Which has more stable isotopes, Cr or Fe?

  24. Pop Quiz • Provide 10 facts about 129I using the chart of the nuclides

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